With the reality of digital television now almost within our grasp, manufacturers of big-screen sets must feel like sky-divers in free fall. Until the 'chute opens with the snap of digital displays finally hitting the stores, the market for large, expensive, conventional rear-projection models might appear to be controlled by nothing but the force of gravity. In a highly unscientific survey, I asked a few dealers around the country whether big-screen television sales were down and whether consumers seemed to be waiting for the coming of the first digital sets. The answer to both questions was a uniform and unequivocal yes.